I?m trying to write a function that will add items to two vectors, and
then to create a third vector that is of the form 1, 2, 3, ?, length of
one of the newly modified vectors.? My problem is that what I?ve written
doesn?t seem to return any of those modifications.? How can I get the
new values to be returned? Here?s the function below.? I want to add a
value, stp, to the end of the stpos vector, a value mcp to the end of
the mcpos vector, and the to create that days vector.? When I call this
function with numerical values for stp and mcp, and then ask to see
stpos, mcpos, and days, nothing has been changed.? How can I fix this?
Here?s the function:
> addday <- function(stp,mcp,stpos,mcpos){stpos<-c(stpos,stp)
+ mcpos<-c(mcpos,mcp)
+ days<-c(1:length(stpos))}
David
You need one more line In your function.
addday <- function(stp,mcp,stpos,mcpos){
stpos<-c(stpos,stp)
mcpos<-c(mcpos,mcp)
days<-c(1:length(stpos))
list(mcpos=mcpos, days=days)
}
This and the other question I just answered together say that you need to
re-read an introduction to R.
On Mon, Mar 30, 2020 at 09:45 David <parkhurs at indiana.edu> wrote:
> I?m trying to write a function that will add items to two vectors, and
> then to create a third vector that is of the form 1, 2, 3, ?, length of
> one of the newly modified vectors. My problem is that what I?ve written
> doesn?t seem to return any of those modifications. How can I get the
> new values to be returned? Here?s the function below. I want to add a
> value, stp, to the end of the stpos vector, a value mcp to the end of
> the mcpos vector, and the to create that days vector. When I call this
> function with numerical values for stp and mcp, and then ask to see
> stpos, mcpos, and days, nothing has been changed. How can I fix this?
>
> Here?s the function:
> > addday <- function(stp,mcp,stpos,mcpos){stpos<-c(stpos,stp)
> + mcpos<-c(mcpos,mcp)
> + days<-c(1:length(stpos))}
>
> David
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
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There is also the possibility that the OP believes that the function calls are passing by reference. On Mon, Mar 30, 2020 at 5:55 PM Richard M. Heiberger <rmh at temple.edu> wrote:> You need one more line In your function. > > addday <- function(stp,mcp,stpos,mcpos){ > stpos<-c(stpos,stp) > mcpos<-c(mcpos,mcp) > days<-c(1:length(stpos)) > list(mcpos=mcpos, days=days) > } > > This and the other question I just answered together say that you need to > re-read an introduction to R. > > > > > On Mon, Mar 30, 2020 at 09:45 David <parkhurs at indiana.edu> wrote: > > > I?m trying to write a function that will add items to two vectors, and > > then to create a third vector that is of the form 1, 2, 3, ?, length of > > one of the newly modified vectors. My problem is that what I?ve written > > doesn?t seem to return any of those modifications. How can I get the > > new values to be returned? Here?s the function below. I want to add a > > value, stp, to the end of the stpos vector, a value mcp to the end of > > the mcpos vector, and the to create that days vector. When I call this > > function with numerical values for stp and mcp, and then ask to see > > stpos, mcpos, and days, nothing has been changed. How can I fix this? > > > > Here?s the function: > > > addday <- function(stp,mcp,stpos,mcpos){stpos<-c(stpos,stp) > > + mcpos<-c(mcpos,mcp) > > + days<-c(1:length(stpos))} > > > > David > > > > ______________________________________________ > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide > > http://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >[[alternative HTML version deleted]]
On 30/03/20 7:55 am, David wrote:> I?m trying to write a function that will add items to two vectors, and > then to create a third vector that is of the form 1, 2, 3, ?, length of > one of the newly modified vectors.? My problem is that what I?ve written > doesn?t seem to return any of those modifications.? How can I get the > new values to be returned? Here?s the function below.? I want to add a > value, stp, to the end of the stpos vector, a value mcp to the end of > the mcpos vector, and the to create that days vector.? When I call this > function with numerical values for stp and mcp, and then ask to see > stpos, mcpos, and days, nothing has been changed.? How can I fix this? > > Here?s the function: > > addday <- function(stp,mcp,stpos,mcpos){stpos<-c(stpos,stp) > + mcpos<-c(mcpos,mcp) > + days<-c(1:length(stpos))}You are probably thinking in terms of "macro languages" rather than in R terms. An R function returns, essentially, the last assigned value. So your function will return the "days" vector; all else disappears into a black hole in cyberspace. Something like the following should do what you want: addday <- function(stp,mcp,stpos,mcpos){ stpos<-c(stpos,stp) mcpos<-c(mcpos,mcp) days<-c(1:length(stpos)) rslt <- list(stpos=stpos,mcpos=mcpos,days=days) rslt } As is so often said on this list, you would do well to spend some time reading and inwardly digesting a basic R tutorial, such as "An Introduction to R", readily available from the R web page (under "Manuals"). HTH cheers, Rolf Turner -- Honorary Research Fellow Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276